U.S. patent application number 13/581728 was filed with the patent office on 2013-03-14 for surgical apparatus for aneurysms.
This patent application is currently assigned to Shanghai MicroPort Medical (Group) Co., Ltd.. The applicant listed for this patent is Qiaorong Jin, Yu Li, Qiyi Luo, Sen Wang, Zhiyong Xie. Invention is credited to Qiaorong Jin, Yu Li, Qiyi Luo, Sen Wang, Zhiyong Xie.
Application Number | 20130066413 13/581728 |
Document ID | / |
Family ID | 44541660 |
Filed Date | 2013-03-14 |
United States Patent
Application |
20130066413 |
Kind Code |
A1 |
Jin; Qiaorong ; et
al. |
March 14, 2013 |
SURGICAL APPARATUS FOR ANEURYSMS
Abstract
The present application discloses a surgical apparatus for
aneurysms comprising: a stent, a delivery guide wire, an introducer
sheath and a microcatheter, wherein: the stent is a self-expanding
stent; the delivery guide wire outside of which the stent is
restrained to is provided in a lumen of the introducer sheath; the
introducer sheather is connected with the microcatheter, with
lumnes communicating, to form a passageway through which the
delivery guide wire and the stent are delivered into a human body.
The surgical apparatus for aneurysms provided in the examples of
the present application is able to deliver and release the stent
which has high density and is super soft to a vascular lesion. A
lattice structure of the stent is of high coverage at the vascular
lesion such that the stent released into the vessel prodeces the
same effects as healing of parent vessel, and thus improves the
treatment of vascular aneurysms.
Inventors: |
Jin; Qiaorong; (Shanghai,
CN) ; Li; Yu; (Shanghai, CN) ; Wang; Sen;
(Shanghai, CN) ; Xie; Zhiyong; (Shanghai, CN)
; Luo; Qiyi; (Shanghai, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Jin; Qiaorong
Li; Yu
Wang; Sen
Xie; Zhiyong
Luo; Qiyi |
Shanghai
Shanghai
Shanghai
Shanghai
Shanghai |
|
CN
CN
CN
CN
CN |
|
|
Assignee: |
Shanghai MicroPort Medical (Group)
Co., Ltd.
Shanghai
CN
|
Family ID: |
44541660 |
Appl. No.: |
13/581728 |
Filed: |
March 2, 2011 |
PCT Filed: |
March 2, 2011 |
PCT NO: |
PCT/CN2011/071447 |
371 Date: |
November 7, 2012 |
Current U.S.
Class: |
623/1.12 |
Current CPC
Class: |
A61F 2/966 20130101;
A61F 2/90 20130101; A61F 2250/0015 20130101; A61B 2017/1205
20130101; A61F 2002/823 20130101; A61B 17/12118 20130101 |
Class at
Publication: |
623/1.12 |
International
Class: |
A61F 2/84 20060101
A61F002/84; A61F 2/88 20060101 A61F002/88 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 2, 2010 |
CN |
201010116448.1 |
Claims
1-18. (canceled)
19. A surgical apparatus for aneurysm, characterized in that it
comprises: a stent, a delivery guide wire, an introducer sheath and
a microcatheter, wherein: the stent is self-expanding; the delivery
guide wire is placed in the inner cavity of the introducer sheath,
with the stent restrained on the outside thereof; and the
introducer sheath is connected with the microcatheter, with lumens
communicating to form a passageway through which the delivery guide
wire and the stent are delivered into a human body.
20. The apparatus according to claim 19, characterized in that the
self-expanding stent is woven with biocompatible metal filaments
and/or polymer filaments.
21. The apparatus according to claim 19, characterized in that two
ends thereof are in a trapezoid structure with an a angle of 30
degree to 60 degree.
22. The apparatus according to claim 20, characterized in that the
self-expanding stent is in a mesh tube structure.
23. The apparatus according to claim 20, characterized in that
surfaces of the self-expanding stent can be coated with an
endothelialization promoting substance, vascular endothelial growth
factor (VEGF), or any other coating layers which may serve the same
purpose.
24. The apparatus according to claim 22, characterized in that the
mesh tube structure has a compression ratio in a range from 1:2 to
1:10 in the radial direction.
25. The apparatus according to claim 24, characterized in that the
mesh tube structure is a uniform lattice structure.
26. The apparatus according to claim 25, characterized in that the
uniform lattice structure has a coverage rate in a range of 20% to
60%.
27. The apparatus according to claim 26, characterized in that the
uniform lattice structure has a coverage rate in a range of 30% to
50%.
28. The apparatus according to claim 24, characterized in that the
mesh tube structure as a lattice structure is non-uniform in the
axial and/or radial direction at the site of an aneurysm, but is
uniform in the rest parts.
29. The apparatus according to claim 28, characterized in that the
non-uniform lattice structure has a coverage rate in the range of
40% to 60%.
30. The apparatus according to claim 28, characterized in that the
uniform lattice structure has a coverage rate in a range of 20% to
40%.
31. The apparatus according to claim 19, characterized in that the
delivery guide wire comprises: a metal core for delivering and
supporting the stent; a spring element covering the metal core; a
boss fixed on the metal core, for providing a pushing force for the
stent during delivery; and a plurality of delivery positioning
elements fixed on the external surface of the spring element or the
metal core, for providing pushing or withdrawing forces for the
stent during delivery.
32. The apparatus according to claim 31, characterized in that the
boss can also be in a high molecular film wound structure.
33. The apparatus according to claim 32, characterized in that a
material of the high molecular film is one of the thermoplastic
elastomers such as PU, silicone rubber and natural rubber.
34. The apparatus according to claim 31, characterized in that
materials of the spring element, the boss and the delivery element
are visualizable materials.
35. The apparatus according to claim 19, characterized in that the
introducer sheath is in a hollow structure.
36. The apparatus according to claim 35, characterized in that the
material of the introducer sheath is a polymeric material.
37. The apparatus according to claim 36, characterized in that the
polymeric material is PTFE material, HDFE material or FEP
material.
38. The apparatus according to claim 19, characterized in that the
microcatheter comprises: a tube body in a step-like hollow
structure with its diameter and hardness decreasing gradually from
the proximal end to the distal end; a stress dispersion tube with
one end connected with the tube body to prevent the tube body from
zigzagging at its proximal end; and an adapting piece used to
connect the introducer sheath with the tube body, which is
connected with the other end of the stress dispersion tube and has
the introducer sheath being inserted therein.
39. The apparatus according to claim 38, characterized in that the
tube body is made of the following materials from inside to
outside: a polymeric material for a smooth layer, metals and/or
polymers for a reinforcement layer, and a polymeric material for a
jacket layer.
40. The apparatus according to claim 39, characterized in that the
distal end of the tube body is further provided with a
visualization element, for indicating the position of the
microcatheter in a blood vessel.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a 35 USC 371 national stage of
International Patent Application No. PCT/CN2011/071447, filed Mar.
2, 2011, which claims priority to Chinese Patent Application No.
201010116448.1, filed Mar. 2, 2010, the entire contents of both of
which are hereby incorporated herein by reference in their
entirety.
TECHNICAL FIELD
[0002] The present application relates to medical instrument, in
particular to a surgical apparatus for aneurysms.
BACKGROUND ART
[0003] The wall of an arterial vessel becomes weak locally due to
diseases, injuries or congenital factors of it. Struck by blood
flow, a weak point of the arterial vascular wall protrudes outward
and dilates gradually, and thus forms an aneurysm. Aneurysms occur
in different parts of the body. Abdominal aortic aneurysm and
intracranial aneurysm are most common. What's fundamental in
aneurysm treatments which aim at reducing the risk of aneurysmal
rupture is to achieve healing of the parent artery and
reconstruction of an anatomical structure of the arterial wall.
[0004] Current endovascular intervention for aneurysms mainly uses
the method of stent-assisted coiling, i.e., delivering a stent of
appropriate density to the pathologically changed blood vessel, and
then delivering the coil through a pore of the stent to the
aneurysm, to achieve the goal of treatment by filling the
aneurysm.
[0005] As the terminal action of an aneurysm embolization occurs in
the aneurysm cavity, by studying the prior art, the applicants have
found: during the process of treating aneurysm with a
stent-assisted coil currently available, the coil shows a mass
effect as evidenced by symptoms of compression of the peritumoral
brain tissue, vital blood vessels and nerves; meanwhile, the fully
dense occlusion rate of coil filling is low, and the postoperative
recurrence is high. In addition, the head end of the coil can
pierce a thin aneurysmal wall easily, which will induce aneurysm
rupture and lead to intraoperative or postoperative death of a
patient directly.
SUMMARY OF THE INVENTION
[0006] In view of the above technical problems, examples of the
present application provide a surgical apparatus for aneurysms with
the following technical solutions:
[0007] a surgical apparatus for aneurysms, comprising: a stent, a
delivery guide wire, an introducer sheath and a microcatheter,
wherein
[0008] the said stent is self-expanding;
[0009] the delivery guide wire is placed in an inner cavity of the
said introducer sheath with the stent restrained on the outside of
it; and
[0010] the introducer sheath is connected with the microcatheter
with lumens communicating to form a passageway through which the
delivery guide wire and the stent are delivered into a human
body.
[0011] Preferably, the self-expanding stent is woven with
biocompatible metal filaments and/or polymer filaments.
[0012] Preferably, surfaces of the self-expanding stent can be
coated with an endothelialization promoting substance VEGF.
[0013] Preferably, the self-expanding stent is in a mesh tube
structure.
[0014] Preferably, the mesh tube structure has a compression ratio
in the range of 1:2 to 1:10 in the radial direction.
[0015] Preferably, the mesh structure is a uniform lattice
structure.
[0016] Preferably, the uniform lattice structure has a coverage
rate in a range of 20% to 60%.
[0017] Preferably, the uniform lattice structure has a coverage
rate in a range of 30% to 50%.
[0018] Preferably, the mesh tube structure as a lattice structure
is non-uniform in the axial and/or the radial direction at the site
of an aneurysm, but is uniform in the rest parts.
[0019] Preferably, the non-uniform lattice structure has a coverage
rate in a range of 40% to 60%.
[0020] Preferably, the uniform lattice structure has a coverage
rate in a range of 20% to 40%.
[0021] Preferably, the delivery guide wire comprises:
[0022] a metal core for delivering and supporting the stent;
[0023] a spring element covering the metal core;
[0024] a boss fixed on the metal core, for providing a pushing
force for the stent during delivery; and
[0025] a plurality of delivery positioning elements fixed on the
external surface of the spring element or the metal core, for
providing pushing or withdrawing forces for the stent during
delivery. The boss can also be in a high molecular film wound
structure.
[0026] Preferably, materials of the spring element, the boss and
the delivery element are visualizable materials.
[0027] Preferably, the material of the high molecular film is one
of the thermoplastic elastomers such as PU, silicone rubber and
natural rubber.
[0028] Preferably, the introducer sheath is in a hollow
structure.
[0029] Preferably, the material of the introducer sheath is a
polymeric material.
[0030] Preferably, the polymeric material is PTFE material, HDFE
material or FEP material.
[0031] Preferably, the microcatheter comprises:
[0032] a tube body in a step-like hollow structure with its
diameter and hardness decreasing gradually from the proximal end to
the distal end;
[0033] a stress dispersion tube with one end connected with the
tube body to prevent the tube body from zigzagging at its proximal
end; and
[0034] an adapting piece used to connect the introducer sheath with
the tube body, which is connected with the other end of the stress
dispersion tube and has the introducer sheath being inserted
therein.
[0035] Preferably, the tube body is made of the following materials
from inside to outside: a polymeric material for a smooth layer,
metals and/or polymers for a reinforcement layer and a polymeric
material for a jacket layer.
[0036] Preferably, the distal end of the tube body is further
provided with a visualization element, for indicating the position
of the microcatheter in a blood vessel.
[0037] As can be seen from the above technical solutions provided
in the examples of the present application, the stent of the
aneurysm surgical apparatus in the examples of the present
application has a high-density lattice structure and thus a high
coverage rate. Especially, due to the non-uniform lattice structure
on the stent with a high coverage rate adjacent to the aneurysm, it
is like that the released stent has reconstructed the arterial wall
at the site of the vascular lesion so that the direction of the
blood flow at the site can be significantly changed. As a result,
blood strikes on the inner wall of the aneurysm have been avoided
leading to an achievement of the purpose of the vascular aneurysm
treatment. Meanwhile, dense mesh filaments of the stent, serving as
a support for the growth or migration of the vascular endothelial
cells, accelerate the growth of intima adjacent to an orifice of
the aneurysm, so that the blood vessel at the lesion site can be
re-covered by intima, thereby achieving a real anatomical cure of
aneurysm.
[0038] Regarding the aneurysm surgical apparatus in the examples of
the present application, the stent is restrained on the delivery
guide wire, and the stent and the delivery guide wire are
pre-mounted into the introducer sheath. During a surgical delivery,
first, the microcatheter is inserted into the pathologically
changed blood vessel and then, the introducer sheath is connected
to the microcatheter. After that, by applying a force to the
delivery guide wire in an axial direction, the stent restrained on
the delivery guide wire is fed from the introducer sheath into the
microcatheter and moved to the vascular lesion. At the end, the
stent is positioned and released at the site of the vascular lesion
by adjusting relative positions between the delivery guide wire and
the microcatheter.
[0039] In addition, when the stent of the aneurysm surgical
apparatus in the examples of the present application is delivered
to and released at the site of the vascular lesion, it can further
serve as a support or a shield for the embolization substance
(e.g., a detachable coil, embolic liquid, etc.) in an aneurysm.
This will ensure that the embolization material is maintained in
the aneurysm only, to keep the parent artery open and to assist the
treament of vascular aneurysm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] Below are provided brief introductions to the figures used
to illustrate the technical solutions in the examples of the
present application or the prior art. Obviously, figures in the
following description are merely examples recorded in the present
application. Those skilled in the art can obtain other figures in
accordance with these figures without further inventive
efforts.
[0041] FIG. 1 is a diagram of the structure of the aneurysm
surgical apparatus provided in the examples of the present
application;
[0042] FIG. 2 is a local section view of the aneurysm surgical
apparatus provided in the examples of the present application;
[0043] FIG. 3 is a diagram of the structure of the stent in the
examples of the present application;
[0044] FIG. 4 is a diagram showing the compression of the stent in
the examples of the present application;
[0045] FIG. 5 is a plane diagram showing the mesh tube structure of
the stent in the examples of the present application;
[0046] FIG. 6 is a diagram showing the structure of the delivery
guide wire in the examples of the present application;
[0047] FIG. 7 is a diagram showing the structure of the boss and
the delivery elements of the delivery guide wire in the examples of
the present application;
[0048] FIG. 8 is a diagram of the structure of the microcatheter in
the examples of the present application;
[0049] FIG. 9 is a diagram showing a stent in the examples of the
present application that is delivered to the site of the vascular
lesion;
[0050] FIG. 10 is a diagram showing how the stent in the examples
of the present application is released in a pushing-and-withdrawing
way; and
[0051] FIG. 11 is a diagram showing how the stent in the examples
of the present application is released in a withdrawing-and-pushing
way.
DETAILED DESCRIPTION OF THE INVENTION
[0052] The most fundamental method of treating an aneurysm is to
achieve a healing of the parent artery and reconstruction of the
anatomical structure of the arterial wall. However, current
endovascular intervention therapy of surgical stent-assisted
coiling presents mass effect, non-dense embolization, and risks of
intraoperative or postoperative aneurysm rupture during the
treatment of aneurysms.
[0053] Examples of the present application provide a surgical
apparatus for aneurysms, which can deliver a stent of high density
and extreme softness to the site of the vascular lesion and release
it. The lattice structure of the stent at the vascular lesion site
has a high coverage rate providing to the stent released into the
blood vessel an effect as of the parent artery has been healed and
thus making a better vascular aneurysm treatment.
[0054] Above are core ideas of the present application. To ensure
that the skilled in the art understand the technical solutions of
the present application better, clear and complete descriptions of
the technical solutions in the examples are provided as follows in
connection with figures in the examples of the present application.
Obviously, the described examples are only part instead of all of
the examples of the present application. Based on the examples of
the present application, all the other examples obtained by the
skilled in the art without inventive efforts should fall within the
protection scope of the present application.
[0055] The examples of the present application provide a surgical
apparatus for aneurysms.
[0056] FIG. 1 is the diagram of the outer structure of the aneurysm
surgical apparatus; FIG. 2 is the local section view of the
surgical vascular apparatus. Combining FIGS. 1 and 2, the aneurysm
surgical apparatus comprises: a stent (1), a delivery guide wire
(2), an introducer sheath (3) and a microcatheter (4).
[0057] The stent (1) used to support the pathologically changed
blood vessel is restrained on the outside of the distal end of the
delivery guide wire (2); the delivery guide wire (2) is provided in
the introducer sheath (3) for delivering the stent; the introducer
sheath (3) is used for pre-mounting the stent (1) and the delivery
guide wire (2). The distal end of the importing sheath (3) is
connected with the microcatheter (4) to allow the delivery guide
wire (2) and the stent (1) entering into the microcatheter (4); and
the microcatheter (4) is used for providing the delivery guide wire
(2) and the stent (1) with a passageway into the pathologically
changed blood vessel during delivery.
[0058] The stent (1) is a highly soft and flexible self-expanding
stent having a continuous mesh tube structure with high density.
The stent (1) is woven with biocompatible metal filaments and/or
polymer filaments. As shown in FIG. 3, each filament of the mesh
tube structure is at a braiding angle .beta. relative to the radial
direction in a range of 15 degree to 85 degree to ensure that the
stent (1) has enough supporting force on radial and circular
directions. As shown in FIG. 3, filament (1-1) continuous in the
axial direction is rotatable around the filament braiding point
(1-2) which serves as a center. This provides sufficient
flexibility to the stent (1) and enables its bending or twisting in
three dimensions. Therefore, when released into a blood vessel, the
stent which will be in a shape more similar to that of the vessel
can conform to the tortuous cerebral vessel and prop up the lumen
morphology at the same time. As shown in FIG. 4, the variable
structure mentioned above further provides the stent (1) with a
high compressible property which can be represented by a
compression ratio up to from 1:2 to 1:10. The compressed stent (1)
can be packed into the introducer sheath or the microcatheter with
a diameter of 0.3 mm to 1.5 mm.
[0059] The mesh tube structure of the stent (1) can be completely
uniform and continuous lattices with a coverage rate in a range
from 20% to 60% as shown in FIG. 5(a). In the examples of the
present application, a coverage rate of the uniform and continuous
lattices from 30% to 50% is chosen. Further, the mesh tube
structure of the stent (1) as a lattice structure can be
non-uniform in the axial and/or the radial direction at the site of
an aneurysm, but be uniform in the rest parts. As shown in FIG.
5(b), after the non-uniform and continuous lattices are delivered
into the blood vessel to a region on or near the orifice of the
aneurysm, this region would have the highest coverage rate of up to
40% to 60%. Such a high coverage rate can change blood flow in the
aneurysm to the greatest extent. The uniform and continuous
lattices in the rest parts have a lower coverage rate in a range
between 20% to 40%. This can provide sufficient supports to normal
vascular walls adjacent to the aneurysm to maintain patency of the
parent artery lumen. Meanwhile, this has also reduced the coverage
of the lattices to the parent artery branches to a best extent to
minimize their impact on blood flow from the parent artery to the
branches.
[0060] As shown in FIG. 6, the delivery guide wire (2) comprises: a
metal core (2-1), a spring element (2-2), a boss (2-3) and a
plurality of delivery positioning elements (2-4), wherein the
structure of the metal core (2-1) from the proximal end to the
distal end is straight-thread-like, step-like with gradually
decreasing diameter and then straight-thread-like again. It is used
for delivering and supporting the stent (1). The spring element
(2-2) covers the straight-thread-like structure at the distal end
and the step-like structure in the middle of the metal core (2-1).
The boss (2-3) is fixed on the metal core (2-1) for providing the
stent (1) with a pushing force during delivery; and the plurality
of delivery positioning elements (2-4) are fixed on the external
surface of the spring element (2-2) or the metal core (2-1) and
positioned in front of the boss (2-3) for providing pushing or
withdrawing forces for the stent during delivery.
[0061] The material for metal core (2-1) can be selected from
stainless steel, nickel-titanium alloy, copper alloy, aluminum
alloy, etc. Moreover, the metal core can be made by grinding one
material, as well as by bonding or welding two materials. In
accordance with vascular tortuosity, the core's diameter usually
reduces gradually from a diameter range of 0.025 inches to 0.012
inches of the straight-thread-like structure at the proximal end to
a range of 0.012 inches to 0.002 inches of the straight-thread-like
structure at the distal end. The straight-thread-like structure at
the proximal end can have a length ranging from 1500 mm to 2000 mm,
the step-like structure in the middle can have a length ranging
from 300 mm to 500 mm, and the straight-thread-like structure in
the distal end can have a length ranging from 10 mm to 30 mm.
[0062] As shown in FIG. 7(a), the boss (2-3) is in a structure of a
metal ring sheet. As shown in FIG. 7(b), the shape of delivery
elements (2-4) has four peripheral polygons with smooth corners.
The number of the delivery element depends on the length of the
stent (1). During a delivery, the delivery elements (2-4) drag the
stent (1) forward and/or backward via frictions between the corners
and the lattices of the stent (1) and/or insertion of the corners
into the lattices of the stent (1). In the examples of the present
application, the number of the delivery element is four.
[0063] The materials of the spring element (2-2), the boss (2-3)
and the delivery positioning elements (2-4) can be selected from
visualizable materials such as tantalum, platinum, gold, tungsten
or polymers.
[0064] The introducer sheath (3) is a polymeric tube in a hollow
structure with low frictional coefficient. Its material can be PTFE
material, HDFE material, FEP material, etc. Stent (1), which is
compressed and restrained on the delivery guide wire (2), is
usually pre-mounted in the introducer sheath (3). During a
delivery, the delivery guide wire (2) is used to help push the
stent (1) from the introducer sheath (3) into the microcatheter
(4).
[0065] As shown in FIG. 8, the microcatheter (4) comprises: a tube
body (4-1), a stress dispersion tube (4-2), an adapting piece (4-3)
and a visualization element (4-4), wherein the tube body (4-1) is
in a step-like hollow structure with its diameter and hardness
gradually decreasing from the proximal end to the distal end. The
stress dispersion tube (4-2) has one end connected with the tube
body (4-1) to prevent the tube body (4-1) from zigzagging or
bending at its proximal end. The adapting piece (4-3) used to
connect the introducer sheath (3) with the tube body (4-1) is
connected with the other end of the stress dispersion tube (4-2)
and has the introducer sheath (3) being inserted in it. The
visualization element (4-4) is provided at the distal end of the
tube body (4-1) for indicating the position of the microcatheter in
a blood vessel during the surgery.
[0066] The tube body (4-1) has different structures, hardness and
diameters along the axial direction in accordance with the vascular
tortuosity and size of a vessel, wherein its structure is
straight-thread-like, step-like and straight-thread-like
sequentially from the proximal end to the distal end, with a length
range of 80 cm to 160 cm, 20 cm to 40 cm and 4 cm to 8 cm,
respectively. The tube body is of single cavity and comprises
multiple layers, namely a smooth layer composed of polymeric
materials, a support reinforcement layer made by weaving and/or
twisting metals and/or polymers and a jacket layer made by
extruding or bonding polymeric materials of different hardness
along a hardness gradient from inside to outside.
[0067] The aneurysm surgical apparatus in the examples of the
present application is used for intracranial aneurysm surgery. The
skilled in the art should know that by only changing the size, this
aneurysm surgical apparatus can further be applied to abdominal
aneurysm surgery or aneurysm surgeries for other parts of the body.
These modifications should also be considered as within the
protection scope of the present application.
[0068] During a delivery in an aneurysm surgery performed with the
said aneurysm surgical apparatus, first, the microcatheter (4) is
fed from a surgical wound into the blood vessel, then the distal
end of the tube body (4-1) of microcatheter (4) is delivered to be
close to the vascular lesion site according to the position
indicated under X-rays by the visualization element (4-4) on the
microcatheter. The stent (1) bound to the delivery guide wire (2)
and compressed in the introducer sheath (3) is fed into the
microcatheter by the application of an axial force to the delivery
guide wire (2). Following positions of the spring element (2-2) the
boss (2-3) and the delivery positioning elements (2-4) on the
delivery guide wire (2) visualized under X-rays, the stent (1) is
navigated to the vascular lesion site as shown in FIG. 9.
[0069] Regarding the process of releasing the stent, as shown in
FIG. 10, it can be carried out by pushing the guide wire (2) first
so that the frontal end of the stent (1) is released then by
withdrawing a segment of the microcatheter (4), and so on and so
forth to deploy the stent in a pushing-and-withdrawing way. Also as
shown in FIG. 11, the process can be carried out by withdrawing a
segment of the microcatheter (4) first so that the frontal end of
the stent (1) is released then by pushing the delivery guide wire
(2), and so on and so forth to deploy the stent in a
withdrawing-and-pushing way. Both methods can release the stent (1)
to the site of the vascular lesion. Their difference lies in the
distance between the distal end of microcatheter (4) and the
aneurysm orifice before the stent (1) is released.
[0070] During the release, inaccurate positioning of the stent (1)
may happen, so that the stent (1) does not evenly cover the neck of
the aneurysm. In this case, the position of the stent (1) can be
adjusted in two ways by utilizing the corners of the delivery
positioning elements (2-4) on the delivery guide wire (2) which can
rub and/or are inserted into the lattices of the stent (1). One way
is to keep the position of the delivery guide wire (2) fixed and
push the microcatheter (4) slowly to take the stent (1) slowly back
into the microcatheter (4) again; the other way is to keep the
position of the microcatheter (4) fixed and withdraw the delivery
guide wire (2) slowly to bring the stent (1) slowly back into the
microcatheter (4) again. After the stent (1) is in the
microcatheter (4) again through either way mentioned above, it will
be repositioned and redeployed.
[0071] In addition, when the stent in the aneurysm surgical
apparatus in the examples of the present application is delivered
and released to the site of a vascular lesion, it can further serve
as a support or a shield for the embolization substance (e.g., a
detachable coil, embolic liquid, etc.) in an aneurysm, This will
ensure that the embolization material is maintained in the aneurysm
only, to keep the parent artery open and to assist the treatment of
vascular aneurysm.
[0072] The stent of the aneurysm surgical apparatus in the examples
of the present application has a high-density lattice structure and
thus a high coverage rate. Especially, due to the non-uniform
lattice structure on the stent with a high coverage rate adjacent
to the aneurysm, it is like that the released stent has
reconstructed the arterial wall at the site of the vascular lesion
so that the direction of the blood flow at the site can be
significantly changed. As a result, blood strikes on the inner wall
of the aneurysm have been avoided leading to an achievement of the
purpose of the vascular aneurysm treatment. Meanwhile, dense mesh
filaments of the stent, serving as a support for the growth or
migration of the vascular endothelial cells, accelerate the growth
of intima adjacent to an orifice of the aneurysm, so that the blood
vessel at the lesion site can be re-covered by intima, thereby
achieving a real anatomical cure of aneurysm.
[0073] Regarding the aneurysm surgical apparatus in the examples of
the present application, the stent is restrained on the delivery
guide wire , and the stent and the delivery guide wire are
pre-mounted into the introducer sheath. During a surgical delivery,
first, the microcatheter is inserted into the pathologically
changed blood vessel and then, the introducer sheath is connected
to the microcatheter. After that, by applying a force to the
delivery guide wire in an axial direction, the stent restrained on
the delivery guide wire is fed from the introducer sheath into the
microcatheter and moved to the vascular lesion. At the end, the
stent is positioned and released at the site of the vascular lesion
by adjusting relative positions between the delivery guide wire and
the microcatheter.
[0074] What are described above are only specific embodiments of
the present application. Note that the skilled in the art can
further make changes and modifications without departing from the
principles of the present application. And such changes and
modifications should also be considered as within the protection
scope of the present application.
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